Wyniki wyszukiwania - BazTech

1

Phenotypic and Genotypic Variation of Declining Segetal Flora : The Case of Stachys annua (Lamiaceae) Populations Established in North-Eastern Poland

Skrajna T., Kubicka H., Gozdowski D.

Polish Journal of Ecology

|

2018

|

Vol. 66, nr 1

23--35

EN

Stachys annua is a short-lived archaeophyte. In Poland it has been classified as threatened with extinction (VU). It prefers carbonate soils and occurs as a weed in cropped and stubble fields in traditionally farmed areas. Study of the occurrence of Stachys annua in North-Eastern Poland was conducted in 2009-2012 at four sites where the species occupied a minimum area of 30 m2 and occurred at each stage of a 4-year crop rotation (spring cereals, winter cereals, tuber crops and stubble fields). The floristically richest communities (25-34 species) were established in unploughed stubble fields, regardless of the habitat conditions. Phytocenoses with S. annua included rare species as demonstrated by high values of floristic value index (FV ranges from 25 to 36). Principle Component Analysis and Spearman rank correlations between plant traits and habitat conditions pointed to soil pH as the factor which determined S. annua phenotypic variation, in particular its height and seed production. The greatest phenotypic variation was found on the alkaline habitat, rich in nitrogen. On the other hand, the cluster analysis showed that the studied populations of inert nitrogen-poor habitats were the most similar. Electrophoretic analysis of storage proteins from S. annua seeds revealed a relatively high genetic similarity of studied populations which was reflected in the similarity coefficients — 0.76 and 0.61 by Dice and Jaccard, respectively. In the case of small or fragmented populations this poses a threat associated with inbreeding and genetic drift of S. annua, which indicates that populations of this species in the study area need to be protected from extinction.

2

Impact of the European Beaver Castor fiber on Deadwood Resources in Lowland River Valley – A Case Study in Wigry National Park (NE Poland)

Misiukiewicz W., Piętka S., Bielinis E.

Polish Journal of Ecology

|

2018

|

Vol. 66, nr 3

270--285

EN

The impact of the European beaver Castor fiber on deadwood resources near dams on the rivers of Wigry National Park (northeastern Poland) has been analyzed. The river sampling area was subdivided into the flooded zone, scarp and upland. We found that beaver feeding was limited to the flooded zone and the scarp. Within a distance of 40 m of the river, beavers browsed 75% of all deadwood pieces (wood debris, stumps, dead trees). The wood generated via direct browsing by beavers made up 5% (3.29 m3/ha) of the total wood volume and 35% (641 pieces/ha) of the total number of wood pieces in this region. The beavers mostly left small pieces of wood (with a mean diameter of about 4 cm) at an area after feeding. The deadwood volume and number of pieces were significantly different in front and behind the dam only in the flooded zone. The volume of deadwood in front of the dam in the flooded zone was higher by 65% than behind the dam (102 and 62 m3/ha, respectively), and the number of pieces was higher by 75% (2200 and 1200 pieces/ha, respectively). We prove that beavers generate the majority of dead wood indirectly – by flooding a part of the area. This results leads to conclusion that frequent flooding of a given area may lead to limiting the source of deadwood in the long term. We also confirm that through direct browsing, beavers produce small amounts of thin dead wood with less usefulness for other groups of animals, thus in this way beavers are not able to provide high-quality deadwood resources.

3

Late Glacial and Holocene vegetation changes in the Wigry National Park, NE Poland - new pollen data from three small dystrophic lakes

Fiłoc M, Kupryjanowicz M., Drzymulska D

Studia Quaternaria

|

2014

|

Vol. 31, Nr 1

5--16

EN

The main phases of the Late Glacial and Holocene development of vegetation in the Wigry National Park were reconstructed based on the pollen analysis of sediments from three small dystrophic lakes (Lake Suchar Wielki, Lake Suchar II and Lake Slepe). At the current stage of research, the age of the studied deposits was determined by AMS radiocarbon dating of few samples only. This meant that the chronology of the investigated profiles had to be estimated also indirectly using their palynological correlation with a radiometrically well-dated profile from Lake Wigry. The obtained pollen data confirmed the picture of the postglacial vegetation changes of the Wigry National Park, which was based on earlier studies of Lake Wigry. Furthermore, it documented the existence, mainly in the Preboreal and Atlantic chronozones, of temporary changes in vegetation, which might be a reaction to a short-lived cold fluctuations of climate.